Hamilton's 60 seasons of broadcasting Major League Baseball rank second all-time behind Vin Scully's record of 66 seasons. Although Hamilton broadcast for other clubs, he is best known for his long tenure as the radio voice of the Astros.
Hamilton joined the Astros' radio broadcast team in 1985, and he remained as the primary play-by-play voice until his retirement following the 2012 season. After retiring, Hamilton served as a guest radio commentator for select Astros home games from '13-15, with his final stint in the booth coming on June 28, 2015, during an Astros-Yankees game at Minute Maid Park.